High torque wrench assembly

ABSTRACT

THE WRENCH ASSEMBLY IS FOR VERY HIGH TORQUE APPLICATIONS AND USES A WORM TYPE MECHANISM ADAPTED TO BE POWER DRIVEN. THE BODY OF THE WRENCH HAS A SOCKET TO RECEIVE A LOCKING BAR OR STABILIZING BAR TO HOLD THE WRENCH AGAINST ROTATION, AND THE WRENCH BODY MAY BE UNITARY OF A HINGED OPENING TYPE. A SPECIAL EXTENSION DRIVING ELEMENT, WHICH FITS INTO THE WRENCH INCORPORATES A SPECIAL TORSION TYPE TORQUE INDICATOR PARTICULARLY SUITED TO THE HIGH TORQUE RANGE OF THE WRENCH.

1971 c. F. BATCHELDER 3,564,955

HIGH TQRQUE WRENCH ASSEMBLY 2 Sheets-Sheet 1 Filed Feb. 5, 1969 lllllIlll 1Nvl- TOR. CLARENCE F. BATCHELDER 16mm: & 1400:;

Fig. 3

1971 c. F. BATCHELDER 3,564,955

HIGH TORQUE WRENCH ASSEMBLY 2 Sheets-Sheet 2 Filed Feb INVEN'IOR.CLARENCE F. BATCHELDER Fig. 7

United States Patent O 3,564,955 HIGH TORQUE WRENCH ASSEMBLY Clarence F.Batchelder, 773 N. Mollison, El Cajon, Calif. 92021 Filed Feb. 5, 1969,Ser. No. 796,868 Int. Cl. B25b 17/00 U.S. Cl. 8157.29 8 Claims ABSTRACTOF THE DISCLOSURE The wrench assembly is for very high torqueapplications and uses a Worm type mechanism adapted to be power driven.The body of the wrench has a socket to receive a locking bar orstabilizing bar to hold the wrench against rotation, and the wrench bodymay be unitary or a hinged opening type. A special extension drivingelement, which fits into the wrench, incorporates a special torsion typetorque indicator particularly suited to the high torque range of thewrench.

BACKGROUND OF THE INVENTION The present invention relates to tools andspecifically to a high torque wrench assembly.

In the maintenance of heavy machinery, construction equipment andvehicles it is often necessary to apply a very high torque to tighten orloosen large nuts, bolts and similar elements. Hand wrenches for thispurpose are heavy and require long handles for leverage. Pneumaticimpact wrenches are also used, but accurate control of torque isdifiicult and the common types of torque indicators are not suitable forvery high torque ranges. Geared wrenches are available with reductiondrives of many types, but usually incorporate ratchets and other smallmechanisms which limit the power that can be applied.

SUMMARY OF THE INVENTION The wrench assembly described herein includes arugged wrench unit with a simple worm tym reduction, directly driving acollet which will hold a variety of sockets and other drive elements.The worm can be driven from either end in either direction and thewrench unit has a socket to receive a stabilizing bar, which holds thewrench unit against rotation. An extension driving element fits into thecollet and incorporates a torsion type torque indicator to providedirect indication of the high torque being applied. For use on nut orcollar elements having no open end over which a wrench can be placed,the wrench unit is hinged to open and the collet is split, a singlefastening securing the unit in place.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the wrenchunit and stabilizing bar, the bar being partially in broken line;

FIG. 2 is a sectional view taken on line 22 of FIG. 1;

FIG. 3 is a side elevation view of the complete wrench assembly, withthe torque indicator;

FIG. 4 is a sectional view taken on line 4-4 of FIG. 3;

FIG. 5 is a plan view of the hinged form of the wrench unit, in open andclosed positions;

'FIG. 6 is a plan view of the hinged wrench unit with a stabilizing barattached; and

FIG. 7 is an enlarged sectional view taken on line 7-7 of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The simple rugged structure ofthe wrench assembly makes it particularly suitable for very high torqueapplications, on the order of thousands of foot pounds, but the use isnot necessarily limited to such a range.

The assembly includes three basic parts, a wrench unit 10, a stabilizingbar 12 and a torque indicator 14. In the form shown in FIGS. 1-3, thewrench unit 10 comprises a casing made in two halves 16 and 18, securedtogether by any suitable means such as the screws 20. If screws are usedthe casing half 16 is threaded, but otherwise the two halves areidentical. Each casing half has a circular opening 22 with an internallyundercut circumferential channel 24 to hold a collet 26, the collethaving boss portions 28 which fit closely in openings 22, so that thecollet is rotatable and held in alignment. Integral with collet 26 is acircumferential worm gear 30, which rides in channels 24. The center ofcollet 26 has a multi-sided bore 32, adaptable to square or hexagonalelements, the configuration being well known. A variety of inserts,adapters, socket elements and other accessories may be held in thecollet, depending on the particular use.

At one end of the casing the two halves have barrel portions 34enclosing a cylindrical chamber 36 in which is a worm 38 rotatablymounted in mesh with worm gear 30. "Each end of worm 38 has a stub shaft40 on which is an adapter 42 for connection to driving means. Asillustrated, each adapter 42 has a square socket 44 to provide a secureconnection for a fluid or electric motor, or a crank, the actual sourceof operating power not being critical. At the other end the casing has atapered extended portion 46 with a square, or otherwise non-circularretaining socket 48 extending through both casing halves. In areas oflimited access, or where the structure is convenient, a bar of suitablestrength (not shown) may be passed through socket 48 and allowed to bearagainst adjacent structure, to prevent the wrench unit from rotatingwhile being driven.

Where space permits the wrench unit is held by a laterally extendingstabilizing bar 12, which has a recessed head 50 fitting closely overthe extended end portion 46, the head having a plug 52 which seats insocket 48, as in FIG. 2. The stabilizing bar 12 is thus securely held inplace and may be allowed to bear against convenient structure, orrestrained in any suitable manner to hold the wrench unit againstrotation. If necessary, a simple detent or locking means may be used tohold the stabilizing bar in place on the wrench unit.

Since the commonly used type of torque indicator is not suitable forvery high torque, a special indicator 14 is incorporated into anextension driving element of the wrench. The torque indicator 14comprises a post 54 having flanges 56 and 58 at opposite ends. Atflanged end '56 is a non-circular plug 60 which is held in the bore 32of collet 26, and at the other end is a plug 62 for attachment ofsuitable tools or driven elements. Post 54 is shown as tapering fromboth ends to a reduced diameter central portion 64 so that torque willcause the post to be twisted in the manner of a torsion bar. Thespecific configuration of the post will depend on the range of torque tobe handled and the elasticity of the material used. To provide directindication of torque, a pointer 66 is fixed to flange 56 and extends toflange 58, to be read against a suitable scale 68 on the latter flange.

For operation where access is limited, or for engaging nut or collarelements having no clear end over which the wrench can be placed, themodified wrench unit 70 shown in FIGS. 57 is used. Except for the casingbeing hinged, the wrench unit 70 is similar in structure to wrench unit10 and pertinent portions are correspondingly numbered.

The casing is divided into a drive portion 72, containing the wormdrive, and a gate portion 74 which incorporates the extended end 46,with socket 48. At one side the drive portion and gate portion arepivotally connected by a hinge pin 76 on an axis parallel to the colletaxis so that the gate portion swings in the plane of the casing.Diametrically opposed to hinge pin 76, across opening 22, the gateportion 74 has a projecting boss 78 which fits closely between lugs 80on the drive portion 72, the connection being secured by a retaining pin82 in a common bore 84 through the interfitting boss and lugs. Forconvenience the retaining pin 82 may be attached to the casing, as by abead chain 86.

The collet is diametrically split into two halves 26A and 26B, toseparate with the casing portions. Due to the close fit of the collet inthe casing, no special fastening means is needed to hold the collethalves together when the casing is closed, as in FIG. 6.

Stabilizing bar 12 may be used with the wrench unit 70, or a modifiedstabilizing bar 88 shown in FIGS. 6 and 7 may be used. The stabilizingbar 88 is similar to bar 12 except for an arm 90 which extends along theside of the casing to the position of the retaining pin. For addedconvenience, a retaining pin 92 is mounted on arm 90 and is slidable ina hollow cap 94 fixed on the arm. A stop pin 96 fixed through retainingpin 92 and enclosed within the cap 94, serves to hold the retaining pinon the stabilizing bar at all times, so that a separate pin isunnecessary.

The simple direct worm drive can be made very rugged and is fullyenclosed for protection. While a ratchet or drive reversal means couldbe incorporated, the simple structure is preferred, since the directionof drive rotation can be reversed, or the drive can be changed from oneadapter 42 to the other when necessary.

I claim:

1. A high torque wrench assembly, comprising:

a wrench unit having a casing;

a collet rotatably mounted in said casing and having an accessoryreceiving bore therein, said collet having a peripheral worm gear;

a worm mounted in said casing in driving mesh with said worm gear andhaving a drive connected adapter on at least one end thereof;

said casing having an open ended retaining socket therein, spaced fromsaid collet, a laterally extending rotation preventing stabilizing barbeing received in said socket.

2. The structure of claim 1 in which said elongated stabilizing bar hasa head closely fitting over the portion of said casing containing saidretaining socket, said head having a plug seating closely in saidsocket.

3. The structure of claim 1 and including an extension post having aplug at one end seating in said collet bore and an accessory attachmentportion at the other end, said post comprising a torsion bar and havingtorque indicat ing means thereon.

4. The structure of calim 3, wherein said torque indicating meanscomprises a pointer fixed to one end of said post and a torque scale onthe other end of the post, against which said pointer is read.

5. The structure of claim 1, wherein said casing has a 15 movableportion separated substantially diametrically of the collet and hingedto swing about an axis parallel to the collet axis, and retaining meanssecuring the casing portions together.

6. The structure of claim 5, wherein said collet is split diameticallyto separate with the casing portions.

7. The structure of claim 5, wherein said retaining means includesinterfitting lug elements on the casing portions, With a common boretherethrough substantially parallel to the hinge axis of the movableportion, and a retaining pin removably secured in said common bore.

8. The structure of claim 7 in which said elongated stabilizing bar hasa head closely fitting over at least part of said movable portion, saidhead having a plug seating closely in said socket, and said retainingpin being mounted on said stabilizing bar.

References Cited UNITED STATES PATENTS 2,429,569 10/ 1947 Stewart81--57.29 3,272,037 9/1966 Bruehl 8l57.29 865,544 10/1901 Weimar 8l57.292,787,180 4/1957 Fish 8l57.29 2,151,953 3/1939 Zimmerman 73-439 JAMES L.JONES, 112., Primary Examiner US. Cl. X.R.

